This invention relates to building panels and more particularly to insulated building panels. Insulated panels are familiar to those skilled in the art, particularly panels made for modular buildings. No completely satisfactory method or structure has been found to provide a supporting frame for Styrofoam panels. Applicant is aware of the Styrofoam building panels shown in the book entitled Foam-Core Panels and Building Systems Principles and Practice Plus Product Directory, by Steve Andrews, Cutter Information Corp., 1100 Massachusetts Avenue, Arlington, Me. 02174. U.S.A.